Evaluating fish interactions with hydrokinetic energy devices
November 20, 2025
A deep-water truss trawl operating mid-channel in the Tanana River allows researchers to sample fish at different depths.
䷡’s marine energy team is assessing interactions between devices and the environment as they test hydrokinetic technologies at the Tanana River Hydrokinetic Test Site. That work includes fish interactions with hydrokinetic devices.
This summer, the fish research team with the UAF ϳԹ of Fisheries and Ocean Sciences collaborated with ACEP at the test site, focusing on understanding when, where and how fish move through the Tanana River in Alaska.
The team’s primary objectives were to characterize the timing and distribution of Pacific salmon smolts and resident fish. They also aimed to monitor the downstream migration of salmon and the depths they occupy in the water column.
They sampled fish from shortly after ice breakup in May through August.
Along the river margins, they used fyke nets — traps with rectangular frames on the front and round hoops behind them, often used in relatively shallow water — to sample fish. In the mid-channel of the river, they used a deep-water truss trawl at three depths.
During the sampling period, they caught over 3,700 fish across 12 different species. Salmon smolts made up 43% of the total catch, with most detected in the mid-channel at depths of 1.5 meters and 3-5 meters.
Out-migrating chum salmon smolt (Oncorhynchus keta) captured mid-channel using the deep-water truss trawl.
The ACEP research team is working to simultaneously advance the performance and reliability of hydrokinetic technologies and the understanding of the technology's interactions with the environment. “That is essential for responsible development of this resource,” said Ben Loeffler, research professional and co-director of the Pacific Marine Energy Center at ACEP.
“We are also exploring co-design opportunities, where new insights on these environmental interactions inform changes in the design of the energy system,” he said.
The findings from this study will inform predictive models assessing collision risks associated with hydrokinetic devices.
The CFOS fish team members include Deanna Strohm, Brock Peterson, Cameron Walker and Andrew Seitz.
Watch a video to learn about the interactions of fish with renewable energy in Alaska rivers.